objective: To investigate the changes of spinal cord blood flow (SCBF) after the ischemia and reperfusion injury of the spinal cord and its relation with pathological damages. Methods: Twenty adult Japanese big-ear wh...objective: To investigate the changes of spinal cord blood flow (SCBF) after the ischemia and reperfusion injury of the spinal cord and its relation with pathological damages. Methods: Twenty adult Japanese big-ear white rabbits equally randomized into the control group, 30-min-ischemic group, 60-min-is chemic group and 90-min-ischemic group. All the rabbits in the latter 3 groups were inflicted with the is chemia and reperfusion injury of the spinal cord through selective occlusion of the lumbar artery. SCBF was measured with the hydrogen clearance method and the pathological changes of the injured spinal cord were observed with Nissl’s staining. Results: SCBF during ischemia was 0 ml/100 g/min. During reperfusion, it was recovered to different levels. However, it was still decreased as compared with that before ischemia and that in the control group. The pathological changes of the gray matter were the most significant. The severi ty of the pathological changes decreased in the order from 90-min-ischemic group, 6O-min-ischemic group to 30-min ischemic group. Conclusion: Reversible injury occurs in rabbits after ischemia for 30 min, irreversible injury in those after ischemia for 90 min and partially reversible injury in those after ischemia for 60 min.展开更多
Objective： To study the characteristics of latency of somatosensory evoked potential （SEP） and motor evoked potential （MEP） and the expression of nestin in subventricular zones （SVZ） after persistent focal cere...Objective： To study the characteristics of latency of somatosensory evoked potential （SEP） and motor evoked potential （MEP） and the expression of nestin in subventricular zones （SVZ） after persistent focal cerebral ischemia in rats. Methods： The model of cerebral ischemia in rats was made by middle cerebral artery occlusion （MCAO）. All animals of ischemia were sacrificed after 12 h, 1 d, 3 d, 7 d, and 14 d to observe the changes of latency of SEP and MEP and to detect the expression of nestin, with an immunohistochemical approach. Results： The latencies of P1 （positive wave 1）, N1 （negative wave 1） and P2 （positive wave 2） in SEP were significantly prolonged after MCAO. The latencies of N1 and N2 waves in MEP were postponed gradually and no statistical difference of latency of N1 wave was found in rats at 7 d and 14 d after MCAO. The expression of nestin increased at 12 h, and showed a significant augmentation at 3 d and peaked at 7 d, then declined slightly at 14 d after MCAO. Conclusion： The cerebral ischemia prolonged the latency of EP waves and the expression of nestin was up-regulated and reached the peak at 7 d, showing the ischemia induced the proliferation of nervous stem cells. The SEP and MEP may evaluate the proliferation in SVZ after brain ischemia.展开更多
Objective: To study the effects of MK-801, an antagonist to N-methyl-D-aspartate (NMDA) receptors, on the apoptosis of spinal cord neurons after cord injury and fend cord transplantation in rats. Methods: Wistar rats ...Objective: To study the effects of MK-801, an antagonist to N-methyl-D-aspartate (NMDA) receptors, on the apoptosis of spinal cord neurons after cord injury and fend cord transplantation in rats. Methods: Wistar rats were random- lzed into group A in which the animals were inflicted with spinal cord hemisection and treated with fetal cord transplantation and MK-801, group B in which the fats were injured with cord hemisection and beated with fend cord transplantation but no MK-80l are given and group C in which the rats received similar cord injury and the eavity in their cord was filled with gelfoam. All the rats were .killed on the lst, 3rd, 7th and 14th day after surgery respectively. The sections of the injured segment of the spinal cord were studied with TUNEL (terminal deoxynucleotidal transferase-mediated DUTP-biotin nick end labeling) and the expression of Bcl-2 was observed with immunohistochemistry. The positive cells were quantitatively analyzed with a computer image analysis system. Results: The Seventy of apoptosis of the cord neurons was in the order of group C > group B > group A (P < 0.005) while the ode of the intensity of Bcl-2 expression was grouP A > group B > group C (P < 0.05). Conclusion: Our findings indicate that fetal cord transplantation and the administration of MK-80l, an antagonist to NMDA receptors can attenuate apoptesis of the cord neurons ther spinal cold injury.展开更多
Objective: To investigate the effects of exogenous brain derived neurotrophic factor(BDNF) expression on in- jured spinal cord by being injected into the cord following its reconstruction with adenovirus. Method: A re...Objective: To investigate the effects of exogenous brain derived neurotrophic factor(BDNF) expression on in- jured spinal cord by being injected into the cord following its reconstruction with adenovirus. Method: A reliable rat model with injury of different gradation was established by using a weight-drop apparatus with a laser compression recorder. The replicate-defect recombinant adenoviral vector containing BDNF gene was transferred into the site of injured spinal cord by direct injection. The validity of gene transfer was verified with X-Gal staining. The morphological changes of the injured ax- on were studied quantitatively. The expression of BDNF mRNA, and immunocytochemical reactivity of BDNF and neurofila- ment(NF) in injured cord of rats were observed. Results: It was verified that the spinal coal could be effectively infected by injecting the adenoviral vector into the injured cord, and the reporter gene was expressed. The loss of axons reduced following the in vivo infection of adenoviral vector carrying exogenous BDNF gene after in injury, while more NF immunopositive ax- ons than that of normal spical cord were found. Conclusion: With in vivo transfer of adenovirus vector into the injured site, a certain extent of protection could be provided to the injured axons by increasing local expressions of exogenous DBNF, and renovation of the cytoskeleton in the injured neurons was facilitated. These double effects are both important in gene therapy of spinal cord injuries.展开更多
Somatosensory and corticomotor evoked potentials (SSEP, CMEP) of the rats with acutely injured spinal cord were determined on the 7th, 15th, 30th, 60th, 120th and 240th day after they received implantation of the embr...Somatosensory and corticomotor evoked potentials (SSEP, CMEP) of the rats with acutely injured spinal cord were determined on the 7th, 15th, 30th, 60th, 120th and 240th day after they received implantation of the embryonic spinal cord from 14-day rat embryo into the injured cord. The motor functions of the hindlimbs were also observed. The rats with acute spinal cord injury and those with cord injury treated with the implantation of a piece of skeletal muscle served as the controls. It was found that the motor functions were recovered on the 30th day after implantation but the latent period of both SSEP and CMEP returned to mormal on the 240th day. At that time,the latent period of SSEP and CMEP of the 2 control groups also recovered gradually. It is believed that embryonic spinal cord implantation can affect the recovery of the motor functions of the rats. But more sophisticated methods are needed to clarify the interrelationship of the host cord with the grafts.展开更多
文摘objective: To investigate the changes of spinal cord blood flow (SCBF) after the ischemia and reperfusion injury of the spinal cord and its relation with pathological damages. Methods: Twenty adult Japanese big-ear white rabbits equally randomized into the control group, 30-min-ischemic group, 60-min-is chemic group and 90-min-ischemic group. All the rabbits in the latter 3 groups were inflicted with the is chemia and reperfusion injury of the spinal cord through selective occlusion of the lumbar artery. SCBF was measured with the hydrogen clearance method and the pathological changes of the injured spinal cord were observed with Nissl’s staining. Results: SCBF during ischemia was 0 ml/100 g/min. During reperfusion, it was recovered to different levels. However, it was still decreased as compared with that before ischemia and that in the control group. The pathological changes of the gray matter were the most significant. The severi ty of the pathological changes decreased in the order from 90-min-ischemic group, 6O-min-ischemic group to 30-min ischemic group. Conclusion: Reversible injury occurs in rabbits after ischemia for 30 min, irreversible injury in those after ischemia for 90 min and partially reversible injury in those after ischemia for 60 min.
基金Supported by Special Funds for Excellent Persons of Sichuan Province(05ZQ026-020)Key Program of Science and Technology of Sichuan Province(05SG1866)
文摘Objective： To study the characteristics of latency of somatosensory evoked potential （SEP） and motor evoked potential （MEP） and the expression of nestin in subventricular zones （SVZ） after persistent focal cerebral ischemia in rats. Methods： The model of cerebral ischemia in rats was made by middle cerebral artery occlusion （MCAO）. All animals of ischemia were sacrificed after 12 h, 1 d, 3 d, 7 d, and 14 d to observe the changes of latency of SEP and MEP and to detect the expression of nestin, with an immunohistochemical approach. Results： The latencies of P1 （positive wave 1）, N1 （negative wave 1） and P2 （positive wave 2） in SEP were significantly prolonged after MCAO. The latencies of N1 and N2 waves in MEP were postponed gradually and no statistical difference of latency of N1 wave was found in rats at 7 d and 14 d after MCAO. The expression of nestin increased at 12 h, and showed a significant augmentation at 3 d and peaked at 7 d, then declined slightly at 14 d after MCAO. Conclusion： The cerebral ischemia prolonged the latency of EP waves and the expression of nestin was up-regulated and reached the peak at 7 d, showing the ischemia induced the proliferation of nervous stem cells. The SEP and MEP may evaluate the proliferation in SVZ after brain ischemia.
文摘Objective: To study the effects of MK-801, an antagonist to N-methyl-D-aspartate (NMDA) receptors, on the apoptosis of spinal cord neurons after cord injury and fend cord transplantation in rats. Methods: Wistar rats were random- lzed into group A in which the animals were inflicted with spinal cord hemisection and treated with fetal cord transplantation and MK-801, group B in which the fats were injured with cord hemisection and beated with fend cord transplantation but no MK-80l are given and group C in which the rats received similar cord injury and the eavity in their cord was filled with gelfoam. All the rats were .killed on the lst, 3rd, 7th and 14th day after surgery respectively. The sections of the injured segment of the spinal cord were studied with TUNEL (terminal deoxynucleotidal transferase-mediated DUTP-biotin nick end labeling) and the expression of Bcl-2 was observed with immunohistochemistry. The positive cells were quantitatively analyzed with a computer image analysis system. Results: The Seventy of apoptosis of the cord neurons was in the order of group C > group B > group A (P < 0.005) while the ode of the intensity of Bcl-2 expression was grouP A > group B > group C (P < 0.05). Conclusion: Our findings indicate that fetal cord transplantation and the administration of MK-80l, an antagonist to NMDA receptors can attenuate apoptesis of the cord neurons ther spinal cold injury.
基金Supported by National Natural Science Fundation of China, No. 39670740
文摘Objective: To investigate the effects of exogenous brain derived neurotrophic factor(BDNF) expression on in- jured spinal cord by being injected into the cord following its reconstruction with adenovirus. Method: A reliable rat model with injury of different gradation was established by using a weight-drop apparatus with a laser compression recorder. The replicate-defect recombinant adenoviral vector containing BDNF gene was transferred into the site of injured spinal cord by direct injection. The validity of gene transfer was verified with X-Gal staining. The morphological changes of the injured ax- on were studied quantitatively. The expression of BDNF mRNA, and immunocytochemical reactivity of BDNF and neurofila- ment(NF) in injured cord of rats were observed. Results: It was verified that the spinal coal could be effectively infected by injecting the adenoviral vector into the injured cord, and the reporter gene was expressed. The loss of axons reduced following the in vivo infection of adenoviral vector carrying exogenous BDNF gene after in injury, while more NF immunopositive ax- ons than that of normal spical cord were found. Conclusion: With in vivo transfer of adenovirus vector into the injured site, a certain extent of protection could be provided to the injured axons by increasing local expressions of exogenous DBNF, and renovation of the cytoskeleton in the injured neurons was facilitated. These double effects are both important in gene therapy of spinal cord injuries.
文摘Somatosensory and corticomotor evoked potentials (SSEP, CMEP) of the rats with acutely injured spinal cord were determined on the 7th, 15th, 30th, 60th, 120th and 240th day after they received implantation of the embryonic spinal cord from 14-day rat embryo into the injured cord. The motor functions of the hindlimbs were also observed. The rats with acute spinal cord injury and those with cord injury treated with the implantation of a piece of skeletal muscle served as the controls. It was found that the motor functions were recovered on the 30th day after implantation but the latent period of both SSEP and CMEP returned to mormal on the 240th day. At that time,the latent period of SSEP and CMEP of the 2 control groups also recovered gradually. It is believed that embryonic spinal cord implantation can affect the recovery of the motor functions of the rats. But more sophisticated methods are needed to clarify the interrelationship of the host cord with the grafts.
